Sina, Tecent and Sohu have hundreds of millions of users, and clearly, the Chinese government doesn’t want those services to become forums for discussing popular revolts. It’s been more than 20 years since China had its own brush with rebellion in the Tiananmen Square protests, but images out of Egypt showing protesters standing up to water cannon trucks just as a solitary Chinese man stood up to a column of tanks just off of Tiananmen Square has got to bring back the memories. And those memories will produce a lot of fear among Chinese authorities. If microblogging had been around in those days, as well as text messages, maybe things might have turned out differently for the protesters in China.

The Egyptian government has been trying to stop protests from being organized by shutting down the internet. So far, it hasn’t worked. China, with its infrastructure of censorship already in place, has a much easier job of filtering what gets through to its citizens.